Combustion apparatus



Dec. 20,1938. RA FORESMAN 2,140,523'- COMBUS TION APPARATUS Filed Aug. 26, 1936 Pomar @.FassmAN F'lq, E ATToR Y turesuc'h as, 'for example, wa boiler I2.

1 II may` include ya cylindrical outer Wall I3, ar

, 7 4center column I4 and a horizontal wallmember 50 -I5carried by the outer wall I3 and center column Patented Dec. 20, y1938 ilzxfrflarrrr OFFICE Y g 2,140,523 coMBUs'rioN APPARATUS Robert A. Foresman, vProspect lPark, Pa., assignor to Westinghouse kElectric `8f Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application August 26, 1936, Serial No. 97,879

3 Claims.

j *My invention relates to grate structuresfor combustion apparatus of. the rotatable 'circular Y grate type and it has for anl object to provide an improvedstructure of this kind.

'f5 i "Further objects of my invention are to provvidean improved grate structure which may be Y 'readily manufactured and assembled and which will bereliable in operation. '1 y A still further-object of the invention is to -preai) vent short vcircuiting of air from the Windbox to f 'the combustion chamber around theY periphery r'of the grate.

These and other objects are effected by my invention, as will be apparent from the Afollowing im description and claimsgtaken in connection with ,the accompanyingdrawing, formingalpart of application, Vin which:

j- Figz '1 is a verticalrsectional'view of a boiler j vfurnace having. my improved grate structureap- '30 plied thereto and is taken 'along' theline I-'I of "F1g;2;VV Y Y Fig. 2 isa `plan View of the grate Istructure and 4supporting base shown 'in Fig. 1 with the 'boiler a portion'of the fuel supporting grate memy 35 bers removed; and,

, v Fig.3 'is an inverted view of a grate member Vshown'iny Figs'. 1 and 2.

" `While applicable to various forms of heating structures or furnaces -employing circular grate structures, 'my invention is particularlyadapt- `-able Ato iiuid heating boiler furnacesof the annular, Yrotating Vgrate type, one form Aof Whichis gdisclosed in my copending application, Serial No. 537,332, filed January 3, 1936 and assigned'to the 5*.Wes`tinghonse Electric & Manufacturing Coinzpany. In this form of furnace, fuel is delivered "to-afportion of the grate and Ais progressively 1 burnedas itis advanced through the combustion y space; "the ash being deflected radially'from the :im'grate after the latter has travelled a predeter- I, mined distance, usually somewhat less than 360.

Y r`'Reference will noWVbey hadeto the `drawing i wherein the grate structure, generally indicated atfI'IIisrotatably carried by a rbase member II vv'vliich .may serve tosupporta iiuid heating struc- A I4. ,The wall I5 includes relatively large openfor, rotatably *supporting the grate structure.

5.5i The Walls'of the base II define a Windbox Il be- (Cl. 12s-,182)

f the trackway or wall 15.

ment one with the other.

of the ring 32.

neath the grate I2 which may be supplied with air for combustion in any suitable manner.

As shown in Fig. 1, the boiler may include an outer Water wall member, I8, carried by the wall I3 of the base II,and a center drum I9 having an uid space 2|, which drum I9 may be supported by the center column I4.

In accordance with my invention, the grate structure I0 includes a plurality of frame `segments 22 which are disposed in a circle for de- )K0 lining an annular frame structure. I have shown in Fig. 2 eight such segments constituting the frame but the number employed may be more or less depending upon the size or design of the grate frame. Each segment 22 includes inner 15 and outer arcuate portions23 and 24, respectively, which r'are connected by'radial arms or spoked portions 25 whereby relatively llarge air passages 26 are formed in the segments 22.

'The inner and outer arcuate portions 23 and 530 Y 24 ofithe'assembled segments 22 define annular bearings for the grate i110 and slidably rest upon A groove 21 is cut or suitably'formed inthe 'faces 28 of the vinner arcuate portions 23 within which a ring 29 is disi125 posed. vThe vlatter is rotatably disposed about the center 4column' I4 and locks the 'inner ends ofthe segments 22 vin horizontal alinement vThe ring 29 may function to maintain the grate :structure I0 substantially coaxial with the center kcolumna() I4. Thel outer arcuate portions 24 of 'the seg,- ments 22 are cut away as shown at 3l in Fig. 1 and a Vring 32 is disposed inthe cut-away portion `Vfor maintaining the segments '22 in engagevA. plurality yof 'bolts `33 .235 may be threaded in the respective segments '22 with their'heads extending over the ring'32 as shown in '1, for preventing upward movement The various segments `22 are provided `rwith "depressed portions or seats 13'4 for a #40 vpurposeto be Vreferred to hereinafter.

The fuel 'supporting portion of the grate structure III includes a plurality of arcuate grate members 35 assembled in fa circle upon the frame seg'- vments 22 as bestshown in Fig. 2. Each `of thelt members T35 may include a plurality of projections 36 extending upwardly from the upper surface thereof and a plurality of air openings 31 extending through the projections 36, respectively. It will be understood that other forms of passages for air may be employed as they form no part of the present invention. A grate member of the type shown at 35 inthe present application is, however, disclosed and claimed in my copending application, Serial No. 96,740, led

Projections 39 are formed on the under side of the grate members 35 for engagement with the seats 34 in the frame segments 22. A depressed portion or notch 4I Vis formed on the under face of the grate members 35 adjacent the outer edges thereof and registers with the heads of the bolts 33. Accordingly, excessive movement of the grate members 35 with respect to the frame members 22 is prevented by the bolt 33 and projections 39 which engage the notches 4| and the seats 34, respectively.

Rotation of the grates may be effected in any suitable manner, as by a pawl and ratchet mechanism shown at 44. The latter preferably includes ratchet teeth 45 formed on the under side of the arcuate portions 24 of the frame segments 22. A pawl 46 may be pivotally supported b-y an arm 41 carried by a shaft 48, which pawl engages the teeth 45 as the shaft 48 is oscillated and thereby effects step by step rotation of the grate structure ID. Oscillation of the shaft iseffected in anyl well known manner.

An air seal may be provided at theouter periphery of the grate l0 by Vproviding upturned arcuate flange portions 5| on the upper side of the grate Vmembers 35, which portions 5| define an annular flange above the outer periphery of the grate I0. A fixed annular flange 52 may extend downwardly within the flanges 5| and may have its bottom edge'53 spaced above the members 35. Accordingly, a working space 54 is dened between the flanges 5| and 52 which lls with ash during operation. Flow of air to the Vspace above the grate I0 through the annular vsioned to provide 'clearance between it and the frame segments 22 and functions principally as a Vlocking member for preventing vertical displacement of one segment 22 with respect to another. A defective grate segment 22 may be removed from the grate assembly b-y raising the outer ring32 and withdrawing said frame segment 22 radially from the inner ring ,29. A replacing segment 22 may be inserted radially over the ring 29 and is then locked in place by lowering the outer ring 32. The outer ring 32 may be proportioned to provide clearance between it and the frame segments 22 whereby radial and circumferential expansion of the frame segments 22 is permitted. As described heretofore, the heads of the bolts 33 prevent displacement of the ring 32. l y

Expansion of the grate members 35 is permittedas they rest by gravity upon the frame segments 22 and are not rigidly secured in any manner. objectionable displacement of the members'35 on the frame segments 22 is, however, prevented by the heads of the bolts 33 and by the projections 39 as described heretofore.

From the foregoing, it will be apparent that I have provided an improved form of structure for supporting the grate members of. an annular furnace structure. Y

While I have shown my invention in but one form, it will be obvious to those skilled in Ithe art that it is not so limited, but'is'susce'ptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as areimposed bythe prior art orV as are specically set forth in the appended claims.

What I claim is:

1. In an annular grate structure, the combination of a plurality of segments having inner and outer arcuate portions and arranged in sideby-side relation for defining an annular frame, each of said inner arcuate portions having a slot formed in the inner face thereof, a center column about which the frame segments are disposed, a ring disposed in said slots and encircling the cenkter column, a plurality of grate members carried by the annular frame, and means for rotating the frame and the grate members carried thereby.

2. In an annular grate structure, the combination of a plurality of segments having inner and outer arcuate portions and arranged in side-byside relation for dening an annular frame, each of said inner arcuate portions having a slot formed in the inner face thereof, a center column about which the frame segments are disposed, a ring disposed in said slots and encircling the center column, an outer ring encompassing the segments and maintaining the samein engagement one with the other, a plurality of arcuate grate having air passages therein, means for preventing movement of the grate members with-respect to the grate segments, and means for rotating the frame segments and the grate memvcenter-column'yan outer'ring encompassing the segments and maintaining the same in-engagement one with the other, a plurality of fastening devices secured in said frame segments and havingrespective head porticnsfoverlying the outer ring for maintaining the same in position,l a plu- `members carried by the Yframe segments and l540 

